Inclosed switch



Se t. 23, 1930. H. J. HA'MME RLY INCLOSED SWITCH Filed Oct. 5, 1928 2 Sheets-Sheet y f g a E fl Q Q Q m;

akin 1 6 L Sept. 23, 1930. H. JHHAMMERLY INCLOSED SWITCH Filed Oct. 3, 1928 2 Sheets-Sheet 2 Patented Sept. 23, 1930 UNITED STATES PATENT OFFICE HERMAN J. HAMMERLY, F WALLINGFOBD, CONNECTICUT, ASSIGNOR TO THE TRUE- BULL ELECTRIC MANUFACTURING COMPANY, 01 I'LAINVILLE, CONNECTICUT, A.

CORPORATION OF CONNECTICUT INCLOSED SWITCH Application filed October 8, 1928. Serial No. 810,089.

This invention relates particularly to the class of inclosed switches'which are operated by means oi an external handle and in which each movable switch blade or contact is ar- 5 ranged to simultaneously make or break an electrical contact with each member of a pair of appurtenant stationary contacts to thus efi'ect a doublemake or a double-break in the circuit. It is a well known fact that a doublebreak switch of the preceding description will safely break a circuit of very much greater capacity hen any form of single-break switch of a like size or any form of double-break switch in which the points of contact are not separated simultaneously.

@neadvautage of a double-break switch of this type is that, when the switch is in the 0d osition, the movable contacts are dead and armless and, being dead in that position, the box can made uite a little shallower as it is not necessary to a low clearance space between the movable contacts and the adjacent parts of the inclosing box. In fact, it would not matter electrically if the movable contact actually touches the metal of the box when it is in csition.

@ne ob ect or my invention is to provide a very i pie rugged and pra'ctical form of r switch in which the cost of mancomparatively low.

' set is to provide a double-break notion in which the movable con- 1' pective pairs of stationary a guiding means for the mot d which moves with the movsucli manner as to greatly ting any formed in opening efojec' is provide a double-break a of a form which may use in connection with or a base of other me so provide an inclosed construction in which protected working room for the switch crank and the cross-bar connectors.

Another object is to provide a double-break switch construction having cross-bar connectors extending through the switch base and having metal guide plates for the connectors of such a form that they may readily be secured to a frangible base of slate orequivalent insulating material. s

Fig. 1 is a front view oi a switch embodying my invention the cover being shown open and the switch being of what is commonly termed a meter testing type although the invention is not limited to this particular type.

Fig. 2 is a transverse sectional view showing the switch box closed but with the switch in the open circuit position.

Fig. 8 is a side view and section showing the switch contacts and method of'insulation and operation.

Fig. 4 is aperspective view of the parts of the switch which more particularly involve my present invention.

The box 10 and its cover 11 may be of any suitable type of construction.

The switch proper has a base 12 of insulating material which is supported above the bottom of the box by means of a number of brackets 13 so that there is plenty of working space beneath the base. The base is secured to the brackets by a number of screws 14.

The stationary contacts 15 and 1d are preferably in the form oi spring jaws spaced apart from each other a short distance. The form illustrated employs three pairs of these contact jaws but the number of pairs is unimportant to my present invention. These contact jaws are secured to the basein any suitable manner.

The movable contact or switch blades 17 are mounted bn the outer face of insulating crossbar 18. These blades may be suitably secured as for instance by means of T-shaped anchorage members 19 riveted or otherwise secured to the blades and the anchorage members being secured to the insulating bar by means of an integral tang or rivet portion 20 which extends through an opening 21 in the bar and is riveted over a washer 22 beneath the bar.

These anchorage members may have teeth or shoulders 19'v adapted to be pressed into the insulating bar 18 when the tan is riveted in place. This obviates the necesslty of slotting the cross-bar.

The cross-bar 18 is supported by crank connector rods 23 which preferably have integral tangs which are riveted to the cross-bar. Theseconnectors are guided in slots in plates 24 which are secured to the base by screws 25. Plates 24 may be mounted-on either the front or the back of the base or in pairs in which case, the two plates would be on opposite surfaces and secured together by means of screws or rivets. The base is provided with cylindrical perforations 24' over which the plates 24 are mounted. These holes 24' are cut or drilled large enough-to allow for the free passage of the connector rods 23.

The switch operating member in the form shown consists of the crank shaft 26 which is preferably pivoted .in the opposite sides of the box and has a handle 27 which extends outside of the box. The crank shaft passes beneath the base 14 and engages in slots 28 in the connectors 23.

To close the circuit, the handle 27 is manually moved so that the crank 26 pulls the connectors 23 toward the bottom of the box, and thus draws the switch blade 17 into the contact jaws 15 and 16. When the circuit is to be opened the handle 27. is moved in the opposite direction and the crank 26 thrusts the connectors 23 and the cross-bar 18 with its contact blade 17 outwardly thus breaking the circuit through the blade 17 and the jaws 15 and 16. At the moment of breaking the circuit the insulating cross-bar 18 is interposed,

between the tips of the jaws 15 and 16 so as to intercept and disrupt any are which may tend to form in the opening movement.

B reason :of the insulating cross-bar being gui ed between the adjacent'edges of the stationary contacts and the connectors being closely guided by the slots in the plates, it

will be readily apparent that the movement of the operatin crank or handle will cause the movement 0 the blades in a direction sub-' stantially at right angles to the surface of the base and, at all times, the blades will be' maintained in a relative osition substantially parallel with the sur ace of the base and with the outer ends of the stationary contacts, thus compelling asimultaneous engagement or disengagement of the movable blade with its respectlve pair of stationary contacts.

It is of course necessary that the circuit be opened or closed simultaneously at each respective pair of stationary contacts, therefore the movement of the movable blade must be closely routed and the use of the accurate- 1y punched guide plates makes such a movement poss1b e at a minimum expense. Ob-

viously it would be a very expensive operation to work rectangular or other shaped holes through a slate or marble base to closely fit the connector which passes through the base but, by the use of these guide plates, it is only necessary to drill around hole through the base large enough for the connector to pass through and then secure the comparatively very cheap guide plates in position.

I claim:

1. A switch including an insulating base, a pair of stationary contact jaws mounted on said base, an insulating cross bar movable between and guided by said jaws, a contact blade mounted on said bar and adapted to electrically connect said jaws, a guide plate secured to said base and an actuating connector extending through said guide plate find connected at one end to said insulating 2. A switch including an insulating base, a pair of stationary contactaws mounted on sald base, an insulating cross bar movable between and guided by said jaws, a contact blade carried by the outer edge of said bar and adapted to electrically connect said jaws, an operating crank and an actuating connector extending through said base and operably connected to one end of said crank and secured to said insulating bar at the other end.

' 3. A switch including an insulating base, a number of pairs of stationary contact jaws mounted on the base and spaced apart from each'other, an insulating cross bar movable between the jaws of each respective pair of jaws, contact blades carried by the outer edge of said bar and adapted to electrically connect each respective pair of jaws, an actuating connector extending throu h said base and secured to said insulating ar between said blades, and an operating crank operably connected with said connector.

4. In an electricswitch, an insulating carrier bar, a T shaped anchorage member havin'gits shank extending through said bar and secured thereto, and a switch blade extending at right angles to said bar and secured to the head of said anchorage member.

' 5. In an electric switch, an insulating base of slate-like material having three holes therein, a metallic said base and havmg oppositely disposed screw seats and an intermediate guide slot, screws passing through two of the holes in. said base and secured to the screw seats in said plate, a blade carrying bar and connector secured thereto and guided in said guide slot and extending through the third hole in said base.

6. A switch including a slate base having a cylindrical perforation therein, a metal plate secured to said base and covering said perforation and having a slot in line with guide plate mounted on said perforation, a movable switch member having a connector rod slidable in said plate ang an operating member connected to said r0 5 7. In an electric switch, an insulating carrier bar, a T-shaped anchorage member having a shank extending through said bar and having a head with edges abutting one surface of said bar,.said edges having tooth-like 10 shoulders indented into the edges of said bar, said shank being secured in said bar and. a switch blade secured to the head of said anchorage member and extending in a plane transverse to said bar.

15 HERMAN J. HAMMERLY. 

